The present invention relates to vehicles, particularly road vehicles. More precisely, it relates to the passive safety of such vehicles.
Road vehicles, particularly passenger cars, are at present designed with great attention to safety. It is usual to distinguish between active and passive safety. Active safety is a vehicle""s ability to avoid accidents, while passive safety is its ability to protect its occupants effectively when an accident could not be avoided. Under the latter category are included safety belts, airbags which are inflated in the event of impact, and also the vehicle""s capacity, by its own crushing, to absorb part of the kinetic energy to be dissipated in the event of an impact, while preserving for the occupants a survival cell which is deformed as little as possible.
It is now known to design bodies for passenger cars which have a cabin usually described as undeformable, protected at least at the front of the vehicle by a part that deforms plastically to absorb part of the vehicle""s kinetic energy at the moment of impact, and also to reduce the deceleration to which the passengers are subjected. It is important to limit the value of this deceleration as much as possible, to reduce the risk of injury to the passengers or minimize the severity of injuries. Besides, the aim is to prevent penetration into the cabin of any mechanical element, such as the engine and steering mechanism and control rods connected to the pedal mechanisms. This has sometimes led to designs in which the implantation of the mechanical elements combined with the shape of the bulkhead separating the engine compartment from the cabin cause the engine to slide under the cabin in the event of impact.
The aim of the present invention is to improve the protection of a vehicle""s occupants still more in the event of a frontal collision.
The invention proposes a vehicle having a preferential rolling direction over the ground and comprising:
at the front, a chassis that extends towards the front end of the vehicle where it comprises an impact zone;
a cabin for transporting passengers, the said cabin being self-supporting and having a front edge, with said impact zone being remote from said front edge of the cabin;
a connection element forming a connecting bar, one end of which is articulated to the chassis at a chassis connection zone and the other end of which is articulated to the cabin at a cabin connection zone, the cabin connection zone being positioned at a level higher than the chassis connection zone, and the cabin connection zone being positioned behind the chassis connection zone.
Most of the heavy motorization systems of the vehicle are preferably attached to the chassis. The notion of a preferential rolling direction makes it possible to identify clearly on the vehicle a front and a rear. It therefore also allows zones on the vehicle to be referred to as further or less far back or further or less far forward. It also permits reference, along a vertical direction, to different levels which are higher or less high relative to the ground.
According to the current usage of the term, a chassis is a structure carrying the mechanical elements on the one hand and the cabin on the other hand, and which is the first-order determinant of the structural rigidity of the vehicle, particularly its torsional rigidity. This design technique has been and is still used for numerous 4xc3x974 vehicles. It is known that the self-supporting body technique has led to the suppression of chassis in virtually all touring vehicles produced nowadays. For all that, however, mechanical elements, such as engines, gear-boxes and ground contact elements are not always mounted individually on the body. There exist what are known as cradles or false chassis, which constitute a structure on which a group of mechanical elements is mounted, the cradle itself then being mounted on the body. In this case the cradle is not required to contribute to the rigidity of the body, its main functions being to facilitate vehicle assembly and to contribute towards better isolation of the vibrations.
The vehicle according to the invention has in part the structure of vehicles with a separate chassis, although the presence of a cabin designed to constitute a survival cell for the passengers is only one important aspect of the invention. The mechanical elements are arranged such that their mass does not compromise the protection of the passengers. This explains the recourse to a supporting and working structure separate from the cabin, which both resembles a chassis because the said structure has an inherent rigidity comparable to that expected in classical vehicles, and also resembles the cradle technique in that it does not necessarily extend the full length of the vehicle, and because it is not intended to confer on the cabin the inherent rigidity expected with cabins of the type known as xe2x80x9cundeformablexe2x80x9d. The word xe2x80x9cchassisxe2x80x9d should be understood in this sense in the present invention.
The invention will be better understood from the description below, which concerns a passenger car with four wheels, although the example given is not limiting.